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KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts

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AArch32 CP1x registers are overlayed on their AArch64 counterparts
in the vcpu struct. This leads to an interesting problem as they
are stored in their CPU-local format, and thus a CP1x register
doesn't "hit" the lower 32bit portion of the AArch64 register on
a BE host.

To workaround this unfortunate situation, introduce a bias trick
in the vcpu_cp1x() accessors which picks the correct half of the
64bit register.

Cc: stable@vger.kernel.org
Reported-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2020-06-09 08:40:35 +01:00
parent e8679fedd0
commit 3204be4109
1 changed files with 4 additions and 2 deletions
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6
arch/arm64/include/asm/kvm_host.h
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@ -404,8 +404,10 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg);
* CP14 and CP15 live in the same array, as they are backed by the * CP14 and CP15 live in the same array, as they are backed by the
* same system registers. * same system registers.
*/ */
#define vcpu_cp14(v,r) ((v)->arch.ctxt.copro[(r)]) #define CPx_BIAS IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)
#define vcpu_cp15(v,r) ((v)->arch.ctxt.copro[(r)])
#define vcpu_cp14(v,r) ((v)->arch.ctxt.copro[(r) ^ CPx_BIAS])
#define vcpu_cp15(v,r) ((v)->arch.ctxt.copro[(r) ^ CPx_BIAS])
struct kvm_vm_stat { struct kvm_vm_stat {
ulong remote_tlb_flush; ulong remote_tlb_flush;